Thermodynamical quantum localization in plasma physics?

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jarek
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Thermodynamical quantum localization in plasma physics?

Post by jarek »

Using quantum mechanics to predict particle dynamics is usually related to low energy physics, suggesting that we can nearly forget about it while considering high energy plasma (?)
There are some recent thermodynamical considerations suggesting that situation might be more complicated - that "quantum" densities with strong localization properties seem to be more universal.
The trick is that standard stochastic models like Brownian motion occur to be usually biased in a very subtle way - often emphasize some possibilities without a base for such assumption. It makes that they often only approximate e.g. maximal uncertainty principle, required by thermodynamical models.

There are recently being developed proper thermodynamical models - based on Maximal Entropy Random Walk (MERW).
For regular conditions or short time scales their behavior is similar, however irregularities make that global dynamical equilibrium state can be completely different.
For example Brownian motion leads to nearly uniform probability distribution, while both quantum mechanics and this corrected thermodynamical approach lead to the quantum mechanical ground state probability density - they have very strong localization properties.
To imagine how nontrivial this localization is, see for example electron density in defected lattice of semiconductor: http://physicsworld.com/cws/article/news/41659
Here is PRL paper about localization in the simplest model: http://prl.aps.org/abstract/PRL/v102/i16/e160602
Here is large paper connecting with quantum thermodynamics (my current PhD thesis): http://arxiv.org/abs/1111.2253
And here is simulator to compare conductance in both models.

Applying to plasma physics the fact that properly made thermodynamical model for moving particles has "quantum" statistics is extremely difficult, but the general intuitions for some additional effects is that density could be more likely to localize in "defect-free" regions.
Where "defect" is something making it more difficult for particle to enter, like maybe the wall of tokamak or a charged object ...(?)

Do you have some experience with difficult to explain strong density localization in plasma physics?
And generally - what quantum effects are considered in plasma physics?

jarek
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Joined: Wed May 25, 2011 2:33 pm
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Post by jarek »

Another "quantum" effect which could be not completely negligible (?) in fusion physics is synchronization of quantum phases - it could make there is preferred some local dynamical equilibrium.
To imagine what does it mean, there are great classical analogues of wave-particle duality of Couder - here is video of these experiments:
http://www.youtube.com/watch?v=W9yWv5dqSKk
On this video there is also synchronous movement of multiple particle - could dynamical version of such synchronization be important in some fusion experiments?

This natural understanding of wave-particle duality was started by de Broglie in his doctoral thesis:
that with particle's energy: E = mc^2
comes some internal periodic proces: E = hf
It is reminded in very interesting Hestenes paper, in which there is also described recent experimental confirmation of this effect (called e.g. zitterbewegung): http://fqxi.org/data/essay-contest-file ... e_essa.pdf
Such internal periodic motion creates also periodic wave-like perturbations of surrounding field - giving localized entity also wave nature ... and allow to model particles as solitons, which often have such internal periodic motion (like breathers).
In Couder's experiments they model solitons with internal periodic motion as oil droplets on vertically vibrating liquid surface - constantly creating periodic waves around - interaction with these waves allows for 'quantum effects': interference, tunneling depending on practically random hidden parameters or orbit quatization condition - that particle has to 'find a resonance' with field perturbations it creates - after one orbit, its internal phase has to return to the initial state.
But static pictures are not enough to get a good intuition - I had occasion to see videos on recent congress on emergent quantum mechanics, where Couder had the opening lecture and most of lecturers were excited about these experiments. Fortunately I've recently found youtube video linked above.

ps. Returning to thermodynamical motion models, if someone had problem reading the paper, there is now new greatly improved version.
Here are slides: http://dl.dropbox.com/u/12405967/chaos.pdf
Here is visualized the basic difference of definition and evolution between standard approach and this finally thermodynamical one:
Image

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